Electric fuse



"25' construction 0f the other suitable means. f

PaiemedlJan 16, 1925.

- I JNITED STATES PATENToFFlcE.

, HENRY T. BUSSMAVNN, OF ST. LOUIS, MISSOURI.

ELECTRIC EUsE.

Application *med Kay 7,

" To all whom 'it may concern.'

Beit known that I, HENRY T. BUssMANN, a citizen of the United States,residing'at St. Louis, Missouri, have invented a certain new and usefulElectric Fuse, of which the following is avull, clear, and. exact def`scri tion, such as will enable others skilled in t art to make and usethe same.

My* invention relates to electric fuses and l. refers particularl tothat type'known as the "refllable 'knife b ade cartri ge type; yetv I donot limit my invention to this type assu certain of m improvements arelikewise de s'rralile i'n. ot er types of fuses.

u 'rte object. ofmyinvenepn is e mide afuse that can beY easily and quicy rescribed inthe specifications, I do not limitmy invention-to theform, shape or se shown, or to the several partsthereof, as variousalterations can lbe made without changing. thescope of my invention.

. v1 isa-view 0f-my fuse, having@ sa:

roken out'cto show the tion ent thereof. Fig. 2 is a similar view,SO'degrees removedfromsthe 'tion shown in Fig. 1. Fig.v 3 showeep'reerred form of my termi.

Anal holding" device.- Fig. '4 shows an alter- 8l nateconsruction. .p

Infthe drawings, 6 is other suitable material. 'which is Ypneferaby 10or other means or removably holding the 40 ,cap 9. .This'meinber is'held'by threads 8 or 'any other suitable means and 1s held rotation by It ispreferably fitted inside the casing, -so that when .the fiber shrinks,it serve'stohold the member firmly, although it isobvious'that I mayattach this rlpember outside the asy shown in ig. 4. Y

The fiat blade terminals l2 are removably 13 bybolts 14, or

a; casing, of fiber or 7 is a member,

y connected to the fuse link The innerpreriphery orf the member 7 y isso provided with threads A 191s. l serial No.' 295,372.

shaped as to hold the terminal 12 against rotational movement. While anynon-circular interior of proper dimensions will so hold the terminal, Iprefer to use grooves as shown at 15. One of these members being placedat each end off the casing, with the grooves properly positioned, theterminals stantial alignment with each other.

Tobhold the terminals against longitudinalv movement, Ipliovide aterminal holding device;- which consists preferably of two parts 16.These parts are .pressed against and firmly' .l 1old the terminalsli byreason `12 are held in the same plane and in subof. their tapered out/erperiphery 1'? and thev tapered walls 18 of the cap 9. These parts l areseated. on 'the'member 7 and when 'held in position b the cap attachedto the 'mem` b er, their -ho ding power cannot v be affected by anyshrinkage in the length of the casing.

"Suchshrinkagewould, if the parts were vseated directly on the fibercasin permit them to become loose and release on the terminals.- It isobvious that these parts may' be reversed on the member and theinnerperiphery of the member, arranged eir hold to hold them, inwhich eventthe cap may be projecti'ons '19, so as to entirely surround the terminaland I make these parts of substan-v tial thickness, thereby providingbearing points 20, 20` and 21, 9.1V separated from each other and inconstant spaced relation to Wise movement, if-

. 4Wise movement, I provide the parts Ywith each other. Theseprojections 19 also serve j to entirely close the case.

To prevent the escape offlame or gases on the blowin of the fuse, Iprefer to arrange that all o the openings in the assembled fuse haveindirect angular paths, so that such flame or gas -must pass throughsuch indirect paths -and is, therefore, substantially restricted fromescaping from the fuse. For this reason I provide a portion of theterminal near the-end of the casing with an interrupted surface 22extending completely around the terminal. I also provide such1nterrupted surface on the projections 19 of the washers 16 where theyabut each other and preferably also on that portion of the washers incontact with the terminals in which event such interrupted surface ismade to coincide with the interrupted surface of the terminal.

Such interrupted surface may be grilled, corrugated, channeled, or madeuneven 1n any mannerl that would provide a restricted enit for flame orgas.

It can be readily seen that this interrupted surface also serves to holdthe terminal more rmly against longitudinal movement.

Due to the clearances necessary between the bolts le and the holes inthe terminal and fuse link through which they tion in length of theassemble element oecurs. The shrinkage of fiber also causes variationsin the length of the casing. To overcome these variations I make theinterrupted surface on the terminal substantially wider than thethickness of the parts so that the parts` will always engage aninterrupted surface notwithstanding limited variations in the relativelength of the fusible element and casing. It is obvious that where thesevariations are prevented or where other means me employed for takingcare of these variations, that this interrupted surfaceneed beapproximately only as wide as the thickness of the parts.

What I claim is:

l. In an enclosed knife blade fuse, a casing, a flat blade terminal, amember permanently attached to the casing and adapted to prevent therotation of the terminal and means seated on said member for wedging theterminal and holding it against longitudinal movement.

9.. In an enclosed knife blade fuse, a casing, a member permanentlyattached to the casing adapted to hold a flat blade terminal in apredetermined position against rotation, a fiat blade terminal extendingwithin the casinga tapered holding device seated on said member forholding the terminal against longitudinal movement, and a cap removablyfitted to said member for holding said tapered device tightly againstsaid member. f

3. In an enclosed knife blade fuse, a casing, a terminal, a memberpermanently at tached to the casing, preventing rotational movement ofthe terminal, a tapered holding device seated on said member, a capremovably fitted tosaid member and means in the cap for causing thetapered holding device to press against the terminal to hold saidterminal against longitudinal movement.

e. In an enclosed knife blade fuse, a casing, a terminal, a memberpermanently atpass, a varia,

tached to the casing, preventing rotation of thev terminal and a tapereddevice for restraining the longitudinal movement of the terminal and acap adapted to bear on the tapered device. 5. In an enclosed knife bladefuse, a casing, a cap, a. terminal extending within the casing, atapered terminal holding device, said device having bearing pointssubstantially separated and in constant spaced relation to each other,Vwhereby the edgewise movement of the terminal'relative to the casing issubstantially prevented, the holding device being wedged against thetermi- .nal to prevent the longitudinal movement indirect exit for gaswhen the fuse is blown.

8. In an enclosed fuse, a. casing, a terminal having a portion thereofwith an interrupted surface substantially about its periphery, aterminal holding device adapted tobe wedged against said portion of theterminal and providing an indirect exit for gas when the fuse is blown.

9. Inan enclosed fuse, a casing, a terminal, a tapered terminal holdingdevice consisting of a plurality of parts surrounding thev terminal andhavin interrupted surfaces on the abutting er ges of such parts,providing an indirect exit for gas when the fuse is blown.

10. In an enclosed fuse, a casing, a terminal, a tapered terminalholding device, surrounding the terminal, said terminal and devicehaving interrupted surfaces abutting each other to provide an indirectexit for gas when the fuse is blown. r

l1. In an enclosed fuse, a casin a. terminal, a tapered terminal holdingevice surrounding the terminal, said terminal having an interruptedsurface of greater width than the thickness of the holding device.

12. In an enclosed fuse two members each having a substantially flatface adapted to be placed in abutting relation with the face of theother member; a portion of one of said faces being interrupted toprovide indirect passageways between Said faces for the exit of gases onthe blowing of the fuse.

13. In an enclosed fuse, a plurality of members in abutting relation,one of said members having a portion ofits abuttin surface knurled, toprovide s. plurality o indirect channels between said abutting i membersfor the exit of gases produced on the blowing of the fuse.

14. In an enclosed fuse, a plurality of members in abutting relation oneof said members having variations in a portion of its abutting surfacewhereby indirect passageways with a plurality of bales therein areprovided between the abutting members,

to allow of the exit of gases therethrough on the blowing of the fuse.

15. In an enclosed fuse two members in abutting relation and means onthe members for holding of vthem against relative displacement andproviding a plurality of indirect passages between the members for theexit of gases on the blowing of the fuse.

HENRY T. BUSSMANN.

